How to solve nullreference exception

Question

1.00/5 (1 vote)

See more:

I have EPCIS Class from this i am looking to generate the XML file

C#

EPCISDocumentType EPCISDOC = new EPCISDocumentType();


          EPCISDOC.schemaVersion = Convert.ToDecimal(1.2);
          EPCISDOC.creationDate = DateTime.Now;

          ManifestItem[] Main = new ManifestItem[1];
          Main[0].Description = "DEscription";
          Main[0].LanguageCode = "Code";
          Main[0].MimeTypeQualifierCode = "1";
          Main[0].UniformResourceIdentifier = "1";

          Scope[] scopearray = new Scope[1];

          scopearray[0].Identifier = "Iden";
          scopearray[0].InstanceIdentifier = "In";
          scopearray[0].ScopeInformation[0] = "23";
          scopearray[0].Type = "type";

          Partner[] Sender = new Partner[1];

          Sender[0].Identifier.Authority = "Authority";
          Sender[0].Identifier.Value = "Value";
          Sender[0].ContactInformation[0].Contact = "Contact";
          Sender[0].ContactInformation[0].ContactTypeIdentifier = "Contact";
          Sender[0].ContactInformation[0].EmailAddress = "Contact";
          Sender[0].ContactInformation[0].FaxNumber = "Contact";
          Sender[0].ContactInformation[0].TelephoneNumber = "Contact";

          Partner[] Receiver = new Partner[1];

          Receiver[0].Identifier.Authority = "Authority";
          Receiver[0].Identifier.Value = "Value";
          Receiver[0].ContactInformation[0].Contact = "Contact";
          Receiver[0].ContactInformation[0].ContactTypeIdentifier = "Contact";
          Receiver[0].ContactInformation[0].EmailAddress = "Contact";
          Receiver[0].ContactInformation[0].FaxNumber = "Contact";
          Receiver[0].ContactInformation[0].TelephoneNumber = "Contact";



          EPCISHeaderType EpcisHeader = new EPCISHeaderType();

          EpcisHeader.StandardBusinessDocumentHeader = new StandardBusinessDocumentHeader
          {
              HeaderVersion = "1",
              DocumentIdentification = new DocumentIdentification
              {
                  CreationDateAndTime = DateTime.Now,
                  InstanceIdentifier = "1",
                  MultipleType = true,
                  MultipleTypeSpecified = true,
                  Standard = "Epcis",
                  Type = "1",
                  TypeVersion = "1.2"
              },
              Manifest = new Manifest
              {
                  NumberOfItems = "1",
                  ManifestItem = Main,

              },
              BusinessScope = scopearray,
              Receiver =Receiver,
              Sender = Sender
          };

          EPCISDOC.EPCISHeader.Equals(EpcisHeader);

          //EPCISDOC.EPCISHeader.StandardBusinessDocumentHeader.HeaderVersion = "1.0";
          //EPCISDOC.EPCISHeader.StandardBusinessDocumentHeader.Sender.Equals(Sender) ;
          //EPCISDOC.EPCISHeader.StandardBusinessDocumentHeader.Receiver.Equals(Receiver);

          XmlSerializer serializer = new XmlSerializer(typeof(EPCISDocumentType));
          serializer.Serialize(File.Create("file.xml"), EPCISDOC);

When I assign any value to the object it gives a null Exception

What I have tried:

Can anyone help to identify the error

Posted 15-Dec-21 0:07am

Md.iftequar iqbal

Updated 15-Dec-21 0:24am

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Chris Copeland · Answer 1 · 2021-12-15T00:24:00

You haven't really provided enough context on what lines are erroring but from the looking at the code I can see you're not using arrays correctly. When you declare an array, all elements of that array will be uninitialized, so you need to initialize each element before using them.

C#

ManifestItem[] Main = new ManifestItem[1];
Main[0].Description = "DEscription";

The issue is here, you're trying to change the content of the element at Main[0] but this is going to be null. You need to initialize it like so:

C#

ManifestItem[] Main = new ManifestItem[1];
Main[0] = new ManifestItem();                     <---
Main[0].Description = "DEscription";

And you need to apply the same logic for all of the arrays in the code. Just declaring an array doesn't create each of the elements in the array, each element needs it's own new call.